I have Katans running aktiv and have never noticed or felt that the treble had rounded off. I found that going from passive to aktiv mellowed them out a bit, less bright, but still very energetic, and less fatigue during long listening periods.
What are you doing for the lower end? If the tukans are anything like the katans, the lows are a little slender so adding a muscial sub improved the staging without sucking out the vibrancy.
What are you doing for the lower end? If the tukans are anything like the katans, the lows are a little slender so adding a muscial sub improved the staging without sucking out the vibrancy.